Tests and Improvements
The tests for the rules seem to be going fine. I could continue to write tests for it forever, with each one getting more complex, so it's hard to know how far to go. After all, they can take a long time to write. At the moment, I'm looking to test each RDFS entailment one at a time. Eventually I'll be moving on to how entailments interact, but I'll only go so far with that, as I really want to move on to the next part, which is OWL entailment.

Still, the code (without tests) is checked in. Have a look in the "rules" directory for an example of running the RDFS rules against the RDF for the RDFS rules. ;-)

I had a talk with Andrae today about how RDFS/OWL and how the Rules engine in Kowari works with it. I also showed him some of the internal structure, and he had a couple of ideas that will help with efficiency. I'm starting to accumulate a list. It's frustrating, as I want to make it all as fast as I can, but I also want to make it as functional as I can, and I can only work on one objective at a time. :-(

The efficiency things I want to do are:

• Make the various implementations of Tuples.getRowCount() run in log time, rather than linear time (this needs a count in the nodes of the AVL tree).
• Add a new version of Session.insert() which accepts an Answer rather than a query
• Properly merge the source and destination models for rules if they are the same model
• Keep a map of Constraints to their counts for each rule, and ensure that answers are using these Constraints.

There's more, but I can't think of them at the moment.

Javadoc
I've also been adding some long-needed documentation to the storage layer.

I pair programmed with with DavidM starting 4 years ago. I worked with him on it for over a year before moving onto other things. So I mostly know how it works, but there are subtle changes since I saw it last. Plus it's been nearly 3 years since I last worked in that area. Back when this code was written, David and I were really pushed for time. To help us get it done in time we were told that we could skip the documentation. It allowed us to meet the deadline that we had, but of course we were never given the time to go back and document it like we were supposed to.

It's been an interesting experience coming back to something so complex after so long. I don't remember all of it clearly, but this process of documenting the methods is really helping me work it out. It's also interesting discovering some of the changes which have come about since I last worked on it.